The procedure used to obtain a sample of cerebrospinal fluid is variously called a spinal tap, lumbar puncture, spinal puncture, Quincke's procedure or rachiocentesis. In general, a spinal tap comprises the insertion of a needle into a subject's subarachnoid space of the lumbar region to release cerebrospinal fluid. Cerebrospinal fluid samples may be required for diagnostic purposes, or it may be desirable to release fluid to relieve pressure.
The conventional manner of performing a spinal tap involves, after suitable preparation of the subject, inserting into a lumbar interspace a hollow needle having a distal beveled end. During insertion and extraction the lumen of the needle is typically occluded by a solid stylet which is also beveled at its distal end. The stylet keeps the needle lumen from becoming plugged with tissue during insertion, and prevents tracking of cerebrospinal fluid along the needle pathway (which can lead to infection) during extraction. A hub on the proximal portion of the stylet typically engages with a seat on the proximal portion of the needle to ensure that the distal beveled ends of the stylet and needle are aligned, and to prevent rotation of the fully inserted stylet within the needle lumen.
During a single procedure the stylet may be withdrawn from the needle lumen several times to evaluate whether the needle is within the subarachnoid space; if fluid escapes from the needle lumen the needle tip is in place, if not, the stylet is re-inserted and the needle-stylet combination is repositioned. Once the needle tip is within the subarachnoid space, the stylet is removed and the pressure of the fluid in the subarachnoid space forces fluid out through the needle lumen. To obtain a sample of cerebrospinal fluid conventional sampling techniques require that an open collection vial or other device be held under the hub of the needle to capture fluid as it drips from the needle lumen. Aspiration is typically not used due to potential medical complications in the subject. Contamination of surfaces by dripping cerebrospinal fluid is a frequent occurrence using the conventional cerebrospinal fluid sampling procedure described above. Cerebrospinal fluid can carry pathogens, including the viruses that cause AIDS and hepatitis B.
In view of the foregoing, a first object of the present invention is to provide surgical systems, methods, apparatus for collecting and storing cerebrospinal fluid from a subject.
A further object of the present invention is to provide means for collecting and storing cerebrospinal fluid samples from a subject wherein leakage of cerebrospinal fluid is reduced.
A still further object of the present invention is to provide means for collecting and storing cerebrospinal fluid samples which can be provided to the user in kit form and carried out quickly and conveniently.